document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=37768>Question 37768</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 6.	For the quadratic function  y = -2x^2 + 8x + 1:<BR>\n" );
document.write( "a.	What are the coordinates (values of x and y) at the vertex of the parabola							<BR>\n" );
document.write( "b.	Does this parabola open upward or downward? Explain.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #23580 by </B><A HREF=/tutors/aboutme.mpl?userid=fractalier><B>fractalier(6550)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=fractalier><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=fractalier><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=23580\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given the quadratic function  y = -2x^2 + 8x + 1, we know that the x-coordinate of the vertex lies at -b/2a, or <BR>\n" );
document.write( "-8/[2(-2)] = 2<BR>\n" );
document.write( "The y-coordinate can be found via f(2)...<BR>\n" );
document.write( "-2(2^2) + 8(2) + 1 =<BR>\n" );
document.write( "-8 + 16 + 1 = 9<BR>\n" );
document.write( "Thus the vertex is at (2, 9).<BR>\n" );
document.write( "Since the coefficient of the x^2 term is negative, the graph is concave downward. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );